BESIGHEIM, Germany — Barack Obama in traditional German lederhosen? It may be hard to imagine, but researchers in the U.S. say they have located documents that prove the president has German roots dating to the 1700s.

According to parish records uncovered by experts at the genealogy Web site Ancestry.com, Obama's 6th great-grandfather Johann Conrad Woelflin was born Jan. 29, 1729, in Besigheim, a small town north of Stuttgart on the Enz river where it feeds into the Neckar.

He sailed aboard a ship called "Patience" in 1750 to America, changing his last name to "Wolfley" upon arrival and eventually settling in Middletown, Pennsylvania, according to head genealogist Anastasia Tyler, who oversaw the research.

In Middletown, he married Anna Catherine Schockey in 1756 and had at least six children, including Ludwig Lewis Wolfley — Obama's 5th great grandfather — who was born in 1766, Tyler said.

The investigation was started by the Web site, which determined in 2007 that Obama had Irish ancestry, after researchers decided a few weeks ago it would be fun to try and prove or disprove rumored German ancestry ahead of the president's visit to Dresden on Friday, Tyler said.

"We'd proved the Irish, so we just wanted to see if there was any truth to the rumors of German heritage," she told The AP in a telephone interview. "People supposed a few different lines that went to Germany, and the one that seemed the most plausible was this Wolfley line, so that's the one we concentrated on."

Tracing the ancestry of Obama's mother, Ann Dunham, the investigative team linked Obama back to Wolfley relatively quickly. But it wasn't until last Friday when a researcher was poring over microfilmed documents at the Family History Library in Salt Lake City, Utah, that they got the breakthrough documenting Wolfley's German ties, Tyler said.

Better than simple birth papers, the document — a so-called parish "Seelenregister" or "register of souls" — gave detailed information not only about Wolfley, but also his parents and grandparents.

"That was the absolute key piece to the puzzle," Tyler said. "Not only did it tie Johann Conrad back to Germany ... but it gave us his parents names and these great details."

Among other things, the documents suggest Obama's family involvement in politics began centuries ago — the parish Seelenregister indicates Johann Conrad Woelflin's grandfather, Conrad Woelflin was mayor for 30 years of Orsingen or Oefingen, both towns south of Stuttgart. The old script makes it difficult to read the name of the town exactly, but the Family History Library says a baptism record for one of Conrad Woelflin's sons lists Conrad as a "member of the court" in Oefingen, so that seems most likely.

The documents also show the current U.S. Commander in Chief has something of a military pedigree.

Johann Conrad's father, Johann Martin Woelflin is listed as a military field surgeon, born in 1690. According to the Seelenregister he was involved in much of the tumult of early 18th century Europe power struggles, fighting in France, Sicily, and what is today Romania.

During the 1716-18 Austro-Turkish War he was involved in the famous siege of Temesvar, in which Habsburg Imperial armies led by Prince Eugene of Savoy took the last important Ottoman-Turk stronghold in Hungary, which is today the Romanian city of Timisoara. During the siege, the document notes that Woelflin was injured with an arrow shot from the fortress.

Married to Maria Margaretha Woelflin in 1722, the couple had nine children of whom Obama's ancestor Johann Conrad was number four. The family appears to have moved around a lot; primarily in the Stuttgart area.

Besigheim deputy mayor Klaus Schrempf told APTN he was "very surprised" that Obama could have a connection to his city. But he tracked down a copy of other local church records himself, and located Woelflin's name.

"If this turns out really to be the case, we will extend an invitation to Mr. Obama and if he would come and visit at some stage, it would be a great joy for the city and for the people," he said.

The quaint city dates back to at least 1153 and today has 11,400 residents. Rivers surround the town on three sides, and two medieval towers and a late-Gothic church give it a picturesque silhouette.

At the time of Johann Conrad's birth, it was part of the duchy of Wuerttemberg.

Bernhard Kober, who runs the Cafe zum Hirsch in the old city center, said he always thought Besigheim was "something very special."

"I took it for granted that some great person came from Besigheim," the 47-year-old told APTN. "That it is Barack? That is great for us."

Several other presidents have German backgrounds — perhaps most famously Dwight D. Eisenhower, who as Supreme Allied Commander Europe during World War II directed the western effort to defeat Nazi Germany. The White House did not respond to requests for comment on Obama's German link.

But Ancestry.com spokesman Mike Ward said the site decided to pursue Obama's ancestry purely out of interest.

"We use these types of stories as opportunities to highlight how interesting family history can be — that everyone has an interesting story to tell," he said.